Today I had a story about a United Airlines flight from Phoenix that diverted from O'Hare to Midway this week after part of the right engine backfired.
Passengers on the plane said they heard what sounded like an explosion and saw a burst of flames. The plane landed safely at Midway.

I was a passenger on a United flight from Calgary a couple of years back. I spent much of the trip listening to air traffic control on the headphones, and was a little disturbed by United’s flight planning when after being denied a direct route to O’Hare (due to post storm backups at ORD) the pilot told the controller he didn't have the fuel to circle at Madison. The situation was even more disturbing when after being put into the pattern the pilot was told to slow down because he was gaining on the queue, to which United responded that he didn’t have the fuel to slow down and requested routing to Rockford to refuel before continuing on to O'Hare. We refueled in Rockford and made it to O’Hare, but the entire situation seemed avaoidable.